Part 1

The day 5 challenge actually looks fun!

Our input looks like this:

[D] [N] [C] [Z] [M] [P] 1 2 3 move 1 from 2 to 1 move 3 from 1 to 3 move 2 from 2 to 1 move 1 from 1 to 2

Which is a visual representation of stacks, and so, for once, we have some serious parsing to do, and that means I finally have a good reason to bust out the nom crate.